The tagging of analog CATV (CATV being sometimes referred to hereinafter as cable) signals for leakage detection purposes is known. There are, for example, the systems illustrated and described in U.S. Pat. Nos. 5,608,428; 6,018,358; and, 6,804,826, and references cited in these. The disclosures of these references are hereby incorporated herein by reference. This listing is not intended to be a representation that a complete search of all relevant art has been made, or that no more pertinent art than that listed exists, or that the listed art is material to patentability. Nor should any such representation be inferred.